Option A

The 11-kilometre corridor would follow the Greensborough Highway south and connect with the Eastern Freeway near Bulleen Road.

It's the shortest route with the least amount of tunnelling, which would run under Rosanna, Heidelberg and Viewbank.

Three interchanges are proposed on the route — the first on Manningham Road, the second on Lower Plenty Road, and the third on Grimshaw Street in Watsonia North.

The pros:

Corridor A is the shortest, most direct and, almost certainly, the cheapest.

The NorthEast Link Authority said it was confident the route would provide a more direct alternative to the traffic-jammed roads in the north-east, and would be likely to take trucks off many residential roads such as Rosanna Road, Para Road and Fitzsimons Lane.

It's also believed Corridor A would divert trucks from road cycling routes and popular shopping locations.

Early planning also indicated the road would be a valuable link to several employment centres in the northern region, including La Trobe University and the West Heidelberg industrial hub.

The cons:

Most of Corridor A's shortfalls are linked to environmental concerns. The authority could not guarantee that cultural and heritage spaces would not be affected by the works and it's likely the corridor would involve some environmental impacts associated with surface works.

Works on the proposed corridor, as well as extensive upgrades on the Eastern Freeway, are likely to involve significant disruptions over an extended period.

The politics:

The route runs through the marginal seat of Ivanhoe, which is currently held by second-term Labor MP Anthony Carbines. In the 2014 election, Mr Carbines narrowly defeated Liberal opponent Carl Ziebell on preferences.

The proposed corridor would also go through the seat of Bulleen, which is held by Opposition Leader Matthew Guy.

Bulleen is one of the safest seats in the state and has never fallen into Labor hands.

But John Stone, a planning lecturer at the University of Melbourne, said the road would cut through many sensitive areas that are part of "Melbourne's identity", and that might prove to be a political challenge for both Mr Guy and Mr Carbines.

"Politically, it's hard to get support for major engineering works through sensitive areas," he said.

"For a government to put a road through sensitive environmental areas, people will be rightly anxious as to what that will mean.

"I'm sure there will be people out knocking on doors saying to people that this road will have a major environmental impact while only reducing traffic for a number of years, so that's something the MPs will have to deal with."

Option B

This 24-kilometre corridor would start near Canterbury Road and move north through Donvale and Mitcham, with an interchange at Reynolds Road taking the tollway west through Montmorency, Watsonia and Bundoora.

The authority said the corridor could provide some opportunities for local businesses to access potential customers and workers in the wider area.

But it's believed the road would not greatly improve access for businesses located in emerging employment areas.

The cons:

Long uphill areas on the route are likely to slow down trucks and reduce the road's efficiency.

Although the route could reduce traffic on the Eastern Freeway and Manningham Road, it's unlikely to provide any congestion relief to key north-to-south roads such as Fitzsimons Lane.

The politics:

The safe Liberal seats Vermont and Warrandyte would be affected, but the road would also pass through the marginal Labor seat of Eltham, which Vicki Ward narrowly won in the last election.

Dr Stone said people in metropolitan Melbourne were becoming more sophisticated in their knowledge of road networks and that the construction of Options A or B might not be as big a political win as the Government would be hoping for.

"There used to be this view in state politics, which was that building big roads meant winning the election, but I don't necessarily think that's the case nowadays," Dr Stone said.

"People may think that initially this could relieve traffic and shorten traffic times but ultimately they may think that I'm still going to be on the Eastern Freeway, still going to be on Hoddle Street, and unless the East West Link is built this doesn't really make a lot of sense."

Option C

Similar to Corridor B, but slightly more direct, the 26-kilometre Corridor C would connect to EastLink and not require any upgrades to the Eastern Freeway.

The route also starts near Canterbury Road in Vermont, but has a more direct northerly route through Warrandyte and Eltham before heading west to connect with the Ring Road.

The pros:

The authority said the road would allow for good access to businesses located in major urban centres and wider metropolitan areas.

The proposal also has the potential to divert trucks away from cycling routes.

The cons:

Corridor C does offer opportunities to protect sensitive areas including the Yarra River by tunnelling, but would involve some environmental impacts associated with surface works.

It would provide the ability to reduce truck travel times, however would likely have long inclines which would slow trucks down and reduce efficiency overall.

The politics:

The road would run through the safe Labor seat of Bundoora as well as the safe Liberal seats of Warrandyte and Croydon.

Vicky Ward's seat of Eltham would also be affected by Corridor C.

Dr Ward said the construction of the road could provide a short term boost to Labor that carried through to next year's election.

"People want to get to work quicker or drop their kids off at school on time, so if the Government announce that a road will reduce all of these issues then there could be some political gain there," Dr Stone said.

Option D

The longest and most indirect route, the 40-kilometre Corridor D would connect with EastLink south of Ringwood, and travel east using part of the proposed Healesville Freeway Reserve.

The corridor was initially proposed without a tunnel to cater for large trucks, but investigations found that tunnels and bridges would be required to minimise impacts on sensitive areas.

The pros:

The indirect nature of the road could mean minimal construction disruptions to the transport network.

The limited amount of tunnelling could mean it has less environmental impact and would also mean it would be relatively easy to construct.

The cons:

The length of the road would actually increase travel times and distances and greatly affect the efficiency of freight movement.

The road would extend into an area with low levels of business density and activity, and offer few businesses opportunities to benefit from improved access to customers.

It's also believed the road offers no relief to residential areas that are already being inundated with trucks.

The politics:

Although the route is the most indirect, and local mayors have rejected the proposal, Dr Stone said its lack of disruption to the environment and day-to-day traffic could be a safe political move.

It would also run through several safe Liberal seats including Bayswater and Croydon.

Dr Stone said it's unlikely the option will ever be seriously considered by the Government, but if it was there would be minimal political impact compared to the other options.

"This is an option that bypasses a lot of the sensitive environmental areas," he said.

"It's more about finding a politically acceptable point where you can cross the Yarra, maybe they're thinking if you push the road out more you might get more political support for it but I really don't think that's a goer."